This invention relates to a tape cassette used for a magnetic recording and reproducing apparatus, such as, for example, a video tape recorder (VTR) or the like, and more particularly to a tape cassette such as a video tape cassette, an 8 mm video cassette, D-VCR cassette or the like which is provided therein with a reel brake member for regulating or preventing rotation of tape reels having a tape wound thereon in non-use of the tape cassette and a recording and reproducing apparatus charged therein with such a tape cassette.
In general, a tape cassette has a pair of tape reels received therein which have a tape-like medium wound thereon. Also, the tape cassette has a brake mechanism incorporated therein for keeping the tape reels from being rotated in non-use of the tape cassette. In the brake mechanism which has been used for this purpose, an elastic member such as a torsion coil spring or a leaf spring is used for urging a brake member against indentations of a teeth-like, shape provided on an outer periphery of a flange of each of the tape reels. When the tape cassette thus constructed is charged in a recording and reproducing apparatus, a brake release member of the apparatus is abutted against the brake member to move it against elastic force of the spring, to thereby release the tape reels from the brake member, resulting in the tape reels being rotated.
Unfortunately, when force of a level exceeding elastic force of the elastic member such as strong shock due to dropping of the tape cassette or the like is applied to the tape cassette, the conventional brake mechanism causes movement of the brake member, to thereby release the tape reels from the brake member, leading to rotation of the tape reels, resulting in sagging of the tape, because the brake member is merely forced against the tape reels by only elastic force of the elastic member. Thus, charging of the tape cassette in the recording and reproducing apparatus causes the tape to be caught by a rotation head of the apparatus, leading to problems such as damage to the tape, a failure in traveling of the tape and the like. In the worst case, this causes a failure in ejecting of the tape cassette from the recording and reproducing apparatus.
Another brake mechanism is known wherein a hub brake is provided in association with a pivotal lid, resulting in being locked by the lid. The brake mechanism is disclosed in Japanese Patent Application Laid-Open Publication No. 103725/1994. The brake mechanism requires to form a gap between a lock section of the hub brake and the lid. Unfortunately, this fails in effective and positive locking of the hub brake by the lid and cannot be applied to a tape cassette wherein a lower flange of tape reels is provided with an engagement, like a video cassette tape.
A further reel brake mechanism is proposed wherein a pair of reel brake members are urged independently from each other by means of a spring, to thereby provide the reel brake structure with resistance to impact. The reel brake mechanism is disclosed in Japanese Patent Application Laid-Open Publication No. 89528/1994. However, the mechanism requires to increase elastic force in order to ensure positive locking of the reel brake members. Also, such an increase in elastic force causes increased force to be required for releasing the locking.